Index: ../trunk-jpl/src/m/classes/model.m
===================================================================
--- ../trunk-jpl/src/m/classes/model.m	(revision 24510)
+++ ../trunk-jpl/src/m/classes/model.m	(revision 24511)
@@ -733,6 +733,9 @@
 				help extrude;
 				error('extrude error message');
 			end
+			if numel(md.geometry.base)~=md.mesh.numberofvertices || numel(md.geometry.surface)~=md.mesh.numberofvertices
+				error('model has not been parameterized yet: base and/or surface not set');
+			end
 
 			%Extrude the mesh
 			if nargin==2, %list of coefficients